Could anyone suggest a reason why this code would not close the word document but leave it open in the background. It works on all versions up to 2013,

Code:
  With o_App
                      
                      Set o_Doc = .Documents.Add(szWordPath & szDocumentFilename, False)
                     If CInt(o_App.Version) < 10 Then
                     'Word 97 and 2000
                      o_Doc.Mailmerge.OpenDataSource Name:=GetDBFilenamep(), _
                           ReadOnly:=False, Connection:=szConnection ', _
                            OpenExclusive:=False, SubType:=wdMergeSubTypeWord2000
                      Else
                      'Word xp and higher
                       szQueryName = Replace(szConnection, "QUERY ", "")
                       szTempTextFilePath = GetDBPath() & "/" & szQueryName & ".txt"
                       DoCmd.TransferText acExportDelim, , szQueryName, szTempTextFilePath, True
                       o_Doc.Mailmerge.OpenDataSource _
                       Name:=szTempTextFilePath, _
                       ReadOnly:=True
                      End If
                      o_Doc.Mailmerge.Destination = 0
                       .Visible = True
                       .Activate
                          .WindowState = 1
                      o_Doc.Mailmerge.Execute Pause:=False
                          
                      End With
                      o_Doc.Close 0